The Dandy, the UK's oldest children's comic, will cease weekly print publication and go online only after its 75th anniversary edition in December, publisher DC Thomson has confirmed.

Ellis Watson, chief executive of the Dundee-based publisher's newspaper and magazine operations, said that the 75th anniversary edition on 4 December will include a reprint of the first-ever Dandy, which went on sale in 1937.

Watson said that the future of Dandy – which features cartoon strips including Desperate Dan, the cow-pie eating cowboy, Korky the Cat and Bananaman – will be digital.

"On December 4th, we'll publish our 75th anniversary edition and now that the cat's out of the bag I can confirm that this will be our last print edition," said Watson. "It's what comes online then that will set the tone for the next 75 years. Dan has certainly not eaten his last cow pie. All of The Dandy's characters are just 110 days away from a new lease of life."

Watson said that there would continue to be a Dandy Annual printed, and that branded products such as mugs will continue to be produced.

The last officially audited circulation for the Dandy was 7,489 weekly sales on average in the last six months of 2011. It is priced at £1.99.

In its heyday from the 1950s to the 1980s the comic enjoyed weekly sales of more than 2m.

DC Thomson launched a Dandy iPhone and iPad app in November last year, priced at £1.49.

"I've closed down loopholes to ensure much tighter internal security," said Watson. "We've heard about people trying to find out the plans by hacking into www.dandy.com so we've taken it all offline and moved in to core project offices. We're in lockdown."

DC Thomson has attempted a number of revamps of the Dandy magazine over the last five years in a bid to revitalise sales.

In 2007 an ill-fated move to a fortnightly edition, called Dandy Xtreme, was prompted by research that found its target market had migrated to other media.

"They're too busy gaming, surfing the net or watching TV, movies and DVDs," explained editor Craig Graham at the time. "They still enjoyed the Dandy, but if they were going to buy it themselves they expected more than just 'a comic my dad used to read'."

The revamp was a failure and the Dandy reverted to a weekly publication, including dropping the Xtreme brand, in 2010.

However, between 2010 and the end of 2011 sales plummeted a further 50% from just over 15,000.

"We're counting down 110 days until the big 75th anniversary bash and we're working on some tremendously exciting things," said Watson.

The first issue of Dandy went on sale in 1937 costing 2d, with a free whistle.

An anniversary edition book called The Art and History of the Dandy is already available for sale, and earlier this year Royal Mail released a collection of stamps commemorating Britain's best-loved comic characters including Desperate Dan and Dennis the Menace.

The Cartoon Museum in London is preparing an exhibition celebrating the 75th anniversary, which will open in October.

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• This article was amended on 17 August 2012. The original said that the first issue of Dandy went on sale in 1937 costing 2p rather than 2d. This has been corrected.

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